Hi Steve,
The guy I did this for last used it in a commercial project and paid me USD 2200. I don't expect anyone to pay me this much for a hobby project so I set it to USD 300.
I would love to make it shareware. When I started writing it, that was my intention, but I have put in a lot of work into this and I feel that if I make it shareware, any chance left of me making some money off my work will be lost. I think you know what I mean.
I intend to use this to get some badly needed money for my university education. Once I am through with this, I probably will make it shareware.

Btw, I have put up a site for those interested in more details:
www.geocities.com/u970070/prjTOP.htm